Rapid economic, demographic, and social change characterizes the lower income and transitional countries of the world. Concomitant with the health benefits of such change, there is an emerging pattern of increased morbidity and mortality from noncommunicable diseases. The main goal of the proposed research is to explain how specific components of socioeconomic change affect a set of intermediate health-related behaviors (diet, physical activity, smoking), which in turn affect 2 main child health outcomes (overweight and elevated blood pressure). These outcomes are among the most important risk factors for adult chronic disease. We also explore whether pre- and early postnatal nutritional status reflected by size at birth and stunting at age 2 exacerbate the health risks of rapid development. The research is based on the classic Mosley and Chen health determinants model, and will use structural equations to estimate the relationships. We focus on children because risk factors for adult chronic disease develop in childhood and track into adulthood. We propose a comparative longitudinal study of children in 4 populations at different levels of economic development. The data are from our ongoing prospective studies in Soweto (South Africa), Russia, China and Cebu (Philippines). Each country is characterized by rapid socioeconomic change; each study covers the key years of childhood; and all include detailed measures of socioeconomic status, anthropometry, and many intermediate health-related behaviors measured on large, representative samples of children and their households. Our structural equations models will examine: (1) the relationship of critical components of rapid economic and social change in each country (e.g. income, prices, food availability, technology, family structure, degree of urbanization, mass media) to health-related behaviors; and (2) the relationship of these health behaviors and other proximate factors to overweight and elevated blood pressure. We will explore whether compositional changes, changes in the structure of relationships or both affect health related behavior and whether there is a synergism of key components of threshold levels of factors that predict major shifts in health related behavior and outcomes. We will use the model results to predict consequences of selected social and demographic changes for child health outcomes. Finally, we will compare results across countries to determine whether there is a consistent pattern or structure of relationships across countries at different levels of development.